Oral cancers account for approximately 5% of total cancers in patients. Oral cancers have the fifth lowest 5-year survival rate of major cancers. Most oral cancers are squamous cell carcinoma, developed from precancerous oral leukoplakia. Up to 40% of leukoplakia transform into cancer. Existing approaches for diagnosing leukoplakia transformation are limited to regular surveillance and biopsies. These do not provide effective and non-invasive early diagnosis. Intelligent Optical Systems (IOS) developed an improved photodynamic diagnostic (PDD) system as a sensitive, non-invasive approach for identification of dysplasia and malignancy. In Phase I , a prototype system was successfully constructed and tested. Promising diagnostic results were obtained from animal experiments which demonstrated the feasibility of early diagnosis of oral dysplasia and squamous cell carcinoma. The novelty of the proposed PDD system lies in its use of a low-cost near- infrared laser in combination with fiberoptic sensing technology to excite the photosensitizer 5-aminolevulinic acid. As a result, higher fluorescence intensity is emitted from cancerous tissue than from healthy tissue. Based on Phase I results, IOS will design a highly sensitive PDD system for clinical trial and commercial demonstration for early diagnosis of oral carcinoma transformed from leukoplakia. PROPOSED COMMERCIAL APPLICATIONS: Leukoplakia, the most frequent precancerous lesion of the oral cavity, occurs in 4% of the population in the U.S. Up to 40% of leukoplakia lesions are potentially transformed to oral squamous carcinoma. The proposed PDD system will be very valuable for cost-effective, sensitive, and effective non-invasive early diagnosis of oral cancer. This device is portable, user-friendly, and convenient to be operated in dental and medical offices and clinics. There is a high demand of this kind of PDD device with a broad market for dental and other oncological applications such as gynecology and gastroenterology.